TSH normal range — and why T3 and T4 matter too
A thyroid report is three lines and a printed range beside each one. Most people read the first line, check whether the arrow points up or down, and stop there. That is the half of the report that gets read — and the half that misleads, because TSH runs in the opposite direction to the gland it is asking about.
What is a normal TSH range?
Most adult reports print TSH somewhere between about 0.4 and 4.0 mIU/L. Treat that as the shape of the range rather than as your range. The numbers beside your own result belong to the analyser your sample ran on, and they genuinely move — in pregnancy, with age, and between laboratories running different assay platforms. Two labs can print different ranges and both be correct. That is exactly why yours is printed on your report.
Why does a high TSH mean a slow thyroid?
Because TSH is not a thyroid hormone at all. It is thyroid stimulating hormone — the instruction your pituitary sends the gland. When the gland produces less than the body is asking for, the pituitary raises its voice and TSH climbs. When the gland produces more, the pituitary goes quiet and TSH drops. So the number moves opposite to the thing you are actually curious about. That inversion is the most common misreading of a thyroid report, and it is the reason a TSH is read beside T4 rather than alone.
If my TSH is normal, why test T3 and T4?
TSH tells you what your pituitary thinks. T4 is what the gland actually released — the storage form, most of it travelling bound to protein. T3 is the active form your cells use, converted largely from T4 elsewhere in the body. A TSH sitting comfortably inside its range with an FT4 near the floor of its own range reads very differently from the same TSH with a mid-range FT4, and only one of those two reports lets you see it. That is the whole reason a thyroid profile is a profile.
| Marker | What it tells you | Often printed for adults | In which profile |
|---|---|---|---|
| TSH | The instruction from your pituitary — it rises when the gland is running slow | 0.4 – 4.0 mIU/L | Both profiles |
| Total T4 | The storage hormone the gland releases, most of it travelling bound to protein | 4.5 – 12.0 µg/dL | T3 T4 TSH |
| Total T3 | The active hormone, measured together with its bound fraction | 0.8 – 2.0 ng/mL | T3 T4 TSH |
| Free T4 (FT4) | The unbound part of T4 — steadier when binding proteins shift | 0.8 – 1.8 ng/dL | FT3 FT4 TSH |
| Free T3 (FT3) | The unbound, active fraction your cells actually use | 2.0 – 4.4 pg/mL | FT3 FT4 TSH |
T3 T4 TSH or FT3 FT4 TSH — which one do I book?
Both are on our list. T3 T4 TSH (₹500) reports TSH with total T3 and total T4, and is the more commonly ordered first look. FT3 FT4 TSH (₹700) reports TSH with the free, unbound fractions — the part not riding on protein — which reads more steadily when pregnancy, the pill or certain medicines shift binding-protein levels. You pay for one profile, not both. If a prescription names one, book that one; if you are not sure, send us the prescription on WhatsApp and we will read it back to you before anything is drawn. Both profiles, side by side →
My TSH is slightly above the range. What now?
What a number means for you is your doctor's reading, not ours. What we can tell you is what moves a TSH result on the day it is drawn: broken sleep, a recent illness, the time of morning you gave the sample, and high-dose biotin supplements, which interfere with several assays. A repeat alongside FT4, on the date your doctor sets, is how the picture settles. We print the collection time on every report so the next comparison is a fair one.
Your Smart Report keeps your history, so a second reading is compared against your first rather than against a stranger's. Aira then walks you through each line on WhatsApp in plain language, alongside Dr. Manju's verification — Aira explains and coaches, she never diagnoses or prescribes, and she tells you when something belongs with your doctor. See what a Smart Report looks like →
What to do next
Food. Ghar ka khana, tuned for a steadier morning: protein early — dal, curd, anda, paneer — so your energy is not being borrowed from the third chai of the day. Iodised salt for everyday cooking. If you already take a thyroid tablet, keep the gap your doctor asked for between it and chai, calcium or iron.
Movement. Something your week can actually hold. Twenty minutes of walking after dinner beats the hour you keep postponing, and two short strength sessions — a set of squats and a carry with your grocery bags counts — protect the muscle that carries your daily energy.
Habits. The ones that make your next report readable: give the sample at roughly the same time of morning every time, keep every report in one folder or one photo album, and write down the date you started or changed any tablet, since levels need weeks to settle. Tell us at booking if you are on one.
Booking is a WhatsApp message. Neither profile needs fasting, so any morning slot works, and a routine report is ready in about 6 hours.* Home collection is charged separately and varies by area. Samples are barcoded from collection to analyzer, run on calibrated analyzers, reviewed by a pathologist, and explained in plain language before they reach you. Apoorv Pathology is registered under the UP Clinical Establishments Act.